1. Field of the Invention
The present invention relates to a transflective liquid crystal panel, and more specifically, to a liquid crystal panel in which liquid crystal molecules have both transmissive and reflective functions by using a polymer network.
2. Description of the Prior Art
According to the source of illuminating light, the liquid crystal display can be divided into three kinds, i.e., transmissive, reflective, and transflective modes. The transmissive liquid crystal display has a backlight for producing light. The light produced by the backlight will pass through the liquid crystal panel to let a user see the image displayed on the liquid crystal display screen. The reflective liquid crystal display has a reflective electrode. When displaying the image, the ambient light of the reflective liquid crystal display will enter the liquid crystal display from the observer side of the user and then be reflected by the reflective electrode. The reflected light will pass through the liquid crystal panel again, and finally the user can see the image displayed on the liquid crystal display. In addition, the transflective liquid crystal display both has the liquid crystal display of transmissive mode and reflective mode. In other words, each pixel area comprises both a transmissive area and a reflective area, wherein the transmissive area uses a backlight, and the reflective area uses an ambient light as a light source.
FIG. 1 is a schematic diagram of a prior art transflective liquid crystal panel. As shown in FIG. 1, the transflective liquid crystal panel 10 comprises an array substrate 12, a color filter substrate 14 and a liquid crystal molecules layer 16 disposed between the array substrate 12 and the color filter substrate 14. The array substrate 12 comprises a plurality of pixel areas 18, and each pixel area 18 both comprises a reflective area 181 and a transmissive area 182. The array substrate 12 also comprises a plurality of thin-film transistors (not shown in figures) respectively disposed in each reflective area 181, a plurality of reflective electrodes 20 disposed on the thin-film transistors, and a plurality of transmissive electrodes (not shown in figures) disposed in the transmissive area 182. In addition, there is a dielectric layer 22 between the reflective electrode 20 and the thin-film transistor.
Because the transmissive area 182 of the transflective liquid crystal panel 10 uses backlight, the light will pass through the liquid crystal molecules layer 16 only one time. The reflective area uses the ambient light as a light source, so the light will pass through the liquid crystal molecules layer 16 twice. In such a case, because the phase difference in the reflective area 181 is twice that in the transmissive area 182, the relation of reflectance versus voltage mismatches the relation of transmittance versus voltage while driving the liquid crystal molecules. For this reason, the prior art transflective liquid crystal panel 10 uses a design of a double cell gap to solve the mismatching problem. More specifically, in the prior art transflective liquid crystal panel 10, a function of the dielectric layer 22 disposed under the reflective electrode 20 is to adjust a cell gap of the liquid crystal molecules layer 16. By disposing the dielectric layer 22, the cell gap of the liquid crystal molecules layer 16 in reflective area 181 is smaller than the cell gap in the transmissive area 182, so the phase difference in a light passing through the reflective area 181 is the same with the one in the light passing through the transmissive area 182. Then, the mismatched problem of driving voltages in the reflective area 181 and in the transmissive area 182 is improved. However, a step of fabricating the dielectric layer 22 in the reflective area 181 has to be increased in the double cell gap design of the transflective liquid crystal panel 10. Further, the increased step not only increases process time and cost but also affects product yield. Importantly, a gap of the border between the reflective area 181 and the transmissive area 182 will make the liquid crystal molecules difficult to align, thereby lowering the quality of displayed images. Besides, although the prior art transflective liquid crystal panel 10 has the design of a single cell gap, the method of utilizing the single cell gap uses different controlling electric circuits that respectively drive the reflective area 181 and the transmissive area 182. Therefore, not only is the arranged complexity of the array substrate increased, but also the driving method thereof is more complicated.